1. try to create new instance which need to parse to the call method in muliply threa method.,
2. Singial instance: not to use the member in the signtan instance. otherwise, the thread sync problem will be a problem. which ist just for temp use.
Try to create new one to pass to the method. Lock (thread thread).
3. Therad Sync problemL: common member not invoke the same method.
4.of Couser, some gengeral list member,